THE EFFECT OF S81 WITHIN THE MINIMAL ESSENTIAL REGION (MER) OF THE BNIP3L PROTEIN IN ACTIVATING ORGANELLE DEGRADATION TO DRIVE FIBER LENS DIFFERENTIATION

Lens differentiation begins with epithelial cells that undergo the process of cellular differentiation and remodelling into fiber cells (Bassnet et al., 2011; Menko 2002; Wride, 2011) that then will undergo terminal remodelling processes to eliminate their cellular organelles to achieve mature lens structure and transparency. We sought to determine if Serine 81, within the minimal essential region (MER) of the BNIP3L protein, is required for organelle elimination. Previous studies have shown that levels of phosphorylated P38 MAPK and ERK ½ peaked in the same region as phosphorylated S81 BNIP3L levels, the equatorial epithelium, where organelle degradation is initiated. The use of specific inhibitors of P38 MAPK (SB203580) or ERK ½ (U0126 or PD99089) and P38 MAPK activator Ansiomycin will be used to determine if P38 MAPK or ERK ½ phosphorylates BNIP3L at S81 to induce mitophagy of mitochondria, endoplasmic reticulum, and Golgi apparatus.